Hispanic for me, as long as it's not so thick that I can't understand the speaker. I wonder what mixed accents would sound like, though. Is this actually possible? I'm curious now.

Yes, more specifically when speaking a foreign language though. You tend to pick up the accent of the person who taught you the language, so if you have a native speaker (with a native accent) teaching you and you have a very strong accent it'll get mixed when you speak the language.

Also in the UK where accents are very geographically sensitive and massively varying (seriously, 50 miles and the accent totally changes) having parents with 2 different accents kinda gets mixed in the kid

Hispanic for me, as long as it's not so thick that I can't understand the speaker. I wonder what mixed accents would sound like, though. Is this actually possible? I'm curious now.

Yes, more specifically when speaking a foreign language though. You tend to pick up the accent of the person who taught you the language, so if you have a native speaker (with a native accent) teaching you and you have a very strong accent it'll get mixed when you speak the language.

Also in the UK where accents are very geographically sensitive and massively varying (seriously, 50 miles and the accent totally changes) having parents with 2 different accents kinda gets mixed in the kid

That's really interesting! I'd love to hear examples.

I need an accent index of sorts with examples if one exists. I'm re-working a very old character of mine, and he and his sister have blended Hispanic+Japanese accents. Problem is, when I imagine them talking in my head, I have no clue as to what they should like. Or maybe I should just scrap the accent idea altogether.

Russian! Or any Eastern European accent, really. I also really like Irish accents. I also like the accents that the mafia characters in Baccano have. I'm not sure what those would be, but they're sexy as hell.